Speech recognition systems may be described in terms of several properties including whether they use discrete word vocabularies (typical of large vocabulary recognizers) or grammar-based vocabularies (typical of small vocabulary recognizers), and whether they continuously process an uninterrupted stream of input audio or commence processing on command (typically a “microphone on” or “MICON” event). Recognizers that use control events may terminate recognition on an external event (typically a “microphone off” or “MICOFF” event), completion of processing of an audio buffer, or detection of silence in the buffered audio data. The processed audio stream in any case may be “live” or streamed from a buffer.
It is a common problem of continuously operated recognition systems that they generate large numbers of errors of recognition and spurious recognition output at times that the recognition system is not being addressed. For example, in a vehicle-based speech recognition system, this problem may occur due to audio from the radio, person-to-person conversation, and/or noise. This fact makes the use of a microphone button or other dialog pacing mechanism almost universal in automotive (telematic) speech recognition applications.
It is a common problem of microphone-button paced speech applications that the application user fails to operate the button correctly. The two typical errors are completing the pushing of the microphone-on button after speech has already begun and releasing the microphone-on button (or pushing the microphone-off button) before speech has ended. In either case, some speech intended to be recognized is being cut off due to these errors of operation by the user.
Accordingly, techniques for overcoming errors in speech recognition systems are needed.